The chiral synthesis of potential adenosine deaminase inhibitors is proposed. These include the threo and erythro 2-hydroxynonyladenines as well as the imidazo-(4,5-d)1,3-diazepine ring systems. Biological evaluation of these compounds will be conducted in order to establish the stereochemical requirements for biological activity. The use of microorganisms for the preparation of chiral intermediates as well as the glycosylation of new bases is also proposed.